This invention relates, in general, to electric watthour meters and, specifically, to watthour meter mounting devices.
In the electric utility industry, plug-in, socket-type watthour meters are commonly employed to measure electric power consumption at a residential or commercial building establishment. A cabinet is mounted on an outside wall of the residence or building and contains pairs of terminals which are connected to electric line and electric load conductors. The terminals receive blade contacts on a plug-in watthour meter to complete an electric circuit through the meter between the line and load terminals.
Frequently, it is necessary to disconnect electric power service to the residence or building. However, it is sometimes desirable in such situations, that the watthour meter be left in the cabinet for future service re-connection. Various adapters have been developed for this purpose.
U.S. Pat. No. 4,311,354 discloses such a meter disconnect adapter in the form of a plastic housing having outwardly extending blades which are insertable into the socket terminals in the cabinet. Resilient fingers are mounted within the adapter and receive the contact blades of a watthour meter to connect the meter to the adapter. The fingers are angularly offset from the blades in the adapter so as to mount the watthour meter at a 45.degree. angle from its normal mounting position. This provides a visual indication that the meter is not in a normal operating position even though it is mounted in the socket.
With the introduction of electronic watthour meters utilizing programmable semiconductor memory for storing power usage, time-of-day usage, billing rates, etc., electric power must be maintained on the watthour meter at all times or cannot be interrupted for periods longer than the life of battery backup contained within the meter or the stored memory will be lost and reprogramming of the memory and recharging of the battery backup will be necessary.
Thus, it is desirable to provide a residential or building electrical service disconnect adapter which disconnects the socket line terminals from the socket load terminals when a watthour meter is stored in the adapter and socket; but which provides electric power through the adapter line terminals to power the semiconductor programmable memory and battery charging circuit contained within the watthour meter during storage. It would also be desirable to provide such a service disconnect adapter which provides a visual indication that the electrical service is disconnected while the meter is stored at the socket in the adapter.